High Quality Al2 O 3 Thin Films Prepared by a Novel Two‐Step Evaporation Process

Al 2 O 3 thin films were prepared by electron beam evaporation and their electrical properties were investigated. A novel two‐step evaporation process, in which a very thin film was evaporated first at room temperature and the remaining part was evaporated at 250°C without breaking the vacuum, gave high quality in both insulating and dielectric properties. The reasons for the improvement are discussed and comparisons are made with specimens prepared by usual evaporation process.